Why the Whole world should be vitally intersted in Arsenic

An exmple of a problem we missed till it was serious

National Health Research InsitituteRichard Wilson

Mallinckrodt Research Professor of Physics, emeritusHarvard University

May 20th 2010

Epidemiology is a blunt instrument 

We need an increase of ~10% before we believe it

We depend on large(unwanted) historical exposures from

mistakes of mankind.Can we do better?

1900: mankind asked rats and mice.If a substance was toxic to a rat,

then assumed to be tocic to a man AT A COMPARABLE DOSE

1960: extemded to carcinogenic potency lifetime total exposure and lifetime incidence.

Rats and Mice agreed to within a factor of 10 although

dioxin/saccharin is 100,000

20 human examples for carcinogenic potency but most seemed to agree:

Rats and mice did not get cancer. Why should people?

We ignored warnings from 1886 onHutchinson)

CJ Chen shocked usThe magnitude of the world disaster in

enormous50 times worse than Chernobyl

Only recently has Jack Ng in Brisbanepersuaded mice to get cancer

We want to understand this before we have anoither big disaster.

The next problem:Physical shape and size:

Surface chemistryASBESTOS

Animals tell us little. Serpentine asbestos and amphiboles

are VERY different under an electron microscope

Yet the EPA treats them the same

Even worse!

The world is developing NANOTECHNOLOGY

VERY different surface properiesToxicology of the bulk material tells us little

carbon naotubes can be made to look like asbestos fobers for industrial purposes

they can be woventhey can be fire resistant

BUTAre they like serpentine or like ammphibole fibers?

I have not been to a conference where they even know the questions to ask.

We need the best fundamental scientifc thinking we can get.

You helped the world by reminding us that arsenic is bad

Can you go further?Please help us find and meet

the next challenges!